Our son wanted a science birthday party. There were science experiments and owl pellet dissections; but the biggest hit was the Kermit D. Frog Dissection birthday cake that my wife made.
Step 1: Bake the Cake and Mix Up the Rice Crispy Treats
The cake is simply out-of-box cake mix - any flavor you like. She used Red Velvet just to keep the theme going. Two rounds with a little cutting creates the basic shape nicely. The arms, legs, tongue, and organs get fashioned out of the rice crispy treat mix. Everything is laid out to get the basic scale correct.
Step 2: Start Icing and Dipping
Now that everything has been dry-fit, the icing can be applied to the cake. She uses butter cream icing (food dye for the color needed) and pipes it on using a #18 star tip. The organ were dipped in melting chocolate (different colors for different organs.) The eyes were gummy candies she found somewhere.
Step 3: Create the Skin Flaps
To create the skin flaps, she cut fruit roll-ups to cover the cavity. She then rolled these back to expose the organs.
Step 4: Finish the Internal Details
After rolling the fruit roll-up skin back, she made the dissection pins out of more rice crispy treat mix. The red goo between the organs was red piping gel.
Step 5: Add the Finishing Touch
The finishing touch was the letter from Kermit donating his body to science. The letter sat over the cake for all to witness. Of course we had to explain to the kids what it meant (and for some who Kermit D. Frog was) - but all the adults got a good laugh out of it.